as: Chars

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1 3.6.1.2 Characters
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1 A single character may be written as a single quote immediately followed
1 by that character.  Some backslash escapes apply to characters, '\b',
1 '\f', '\n', '\r', '\t', and '\"' with the same meaning as for strings,
1 plus '\'' for a single quote.  So if you want to write the character
1 backslash, you must write ''\\' where the first '\' escapes the second
1 '\'.  As you can see, the quote is an acute accent, not a grave accent.
1 A newline immediately following an acute accent is taken as a literal
1 character and does not count as the end of a statement.  The value of a
1 character constant in a numeric expression is the machine's byte-wide
1 code for that character.  'as' assumes your character code is ASCII:
1 ''A' means 65, ''B' means 66, and so on.
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